The present invention relates to power transistors and transcalent power devices incorporating such transistors.
The transcalent device is an operable electronic device having an integral cooling system connected to it. Such cooling systems may include a circulating liquid coolant or at least one heat pipe. Many transcalent devices which operate at high current comprise a semiconductor wafer sandwiched between two heat pipes to provide additional cooling of the semiconductor wafer. The two heat pipes are usually joined together with a structural member which protects the edge of the semiconductor device and maintains the semiconductor device under compression. The heat pipes in transcalent devices are in thermal and electrical contact with the semiconductor device.
In a transcalent transistor, means are required to provide for the attachment of a control of gating lead to the base region of the transistor. In a prior art device such as that shown in U.S. Pat. No. 3,739,235 issued to S. W. Kessler Jr. on June 12, 1973 entitled "Transcalent Semiconductor Device," a gate lead is bonded between a gate electrode and a small feed-through pin which is used as the base terminal of a transcalent thyristor. However, in semiconductor devices in which the base current exceeds 20 amperes continuous and 100 amperes pulsed, the feed-through pin and gate lead are inadequate to handle the large current.